A seven day continuous intravenous infusion of cytosine arabinoside in association with a three day schedule of intermittent daily doses of daunorubicin has been shown to be highly effective chemotherapy for the induction of remission in adults with acute non-lymphocytic leukemia. A complete remission rate of 65% is obtained with this combination. Serum muramidase levels appear to accurately reflect disease activity in a large proportion of patients with acute non-lymphocytic leukemia. Carcinoembryonic antigen and serum immunoglobin concentrations do not appear to accurately reflect disease activity. Similarly, biochemical testing of leukemic bone marrow cells does not allow for selection of favorable groups of patients to be treated with cytosine arabinoside (kinasedeaminase ratio) or daunorubicin alone (daunorubicin reductase level). Reverse transcriptase has been identified in the bone marrow cells of leukemia patients prior to treatment and in morphologically normal peripheral cells during complete remission. One interpretation of this data is that morphologically and functionally normal granulocytes in the peripheral blood of leukemia patients in complete remission may be derived from leukemic cells. BIBLIOGRAPHIC REFERENCES: Whang-Peng, Gralnick, H.R., Knutsen, T., Brereton, H., Chang, P., Schechter, G.P. and Lessin, L.: Small F chromosome in myelo- and lymphoproliferative disease. Leukemia Res. 1: 19-30, 1977.